Grate



Sept. 15, 1925.

A. IBALMHIRTH eRikrE original FiledJunelO, 1924 2 Sheets-Sheet l Ayetw y f g Patented Sept. 15, 1925.

UNITED STATES ALFRED BALMFIRTH, or MONTREAL, QUEBEC, CANADA.

GRATE.

Application filed June 10, 1924, Serial Ito-719,199. Renewed June 2, 1925;

To all whom it may concern:

Be it known that I, ALFRED BALMFIRTH, a citizen of the Dominion of Canada, residing at Montreal, in the county of Hochelaga, Province'of Quebec, Dominion of Canada, have invented certain new and useful Improvements in Grates, of which the r following is a specification.

This invention relates to grates, more particularly to the bars thereof, and is designed primarily for use in the burning of low grade fuels, anthracite, screenings and 1 dust, saw-dust, coke breeze, etc., but it is to be understood that a grate set up from grate bars, in accordance with this inven-' tion can be employed for any purposes wherein it is found applicable, and the invention has for its object to provide, in a manner as hereinafter set forth, a grate bar constructed to burn economically the finely divided anthracite dust, screenings and what has been generally considered as refuse in-furnaces generally, andby modifications and the manner of assembling, may be used in household round pot furnaces, or under steam boilers for factory purposes.

A further object of the invention is to provide, in a manner as hereinafter set forth, ported grate bars that will answer respectively for slow combustion fires, as in house heating furnaces, and for high combustion grates as in high pressure boilers for factory or power house work.

Many different kinds of grates have been used in the past for the purpose of burning low grade anthracite fuels, but have been found inefficient through incomplete combustion-or inability to obtain the required amount of steam or heat from a given surface, both of which are caused by inability to obtain combustion over the entire grate surface. As there is an enormous supply of these low grade fuels which are at present unsuitable for general use on account of difficulty of burning them satisfactorily, it is evident that any means whereby they may be rendered available will be 'of material benefit, and to this end the primary object of the invention is to provide a grate composed of bars of suitable material and so constructed that they will produce full and even heat with finely divided fuels over the entire area of the furnace grate, due to the evendistribution of air underslight pressure, discharged at an angle under the fuel and at the surface of the grate.

A further object of the invention is provide, in a manner as hereinafter; set forth, a grate bar which when used in connection with a grate will prevent loss of fine fuel through the grate into the ash pit before the fuel has been completely burned.

A further object of the invention is to provide, in a. manner as hereinafter set forth, a grate'bar so constructed that when a plurality of bars are employed in connection with the grate, will not only prevent loss of fuel, but furthermore will interlock with each other in a ,manner to prevent,

fici'ent in its use, and comparatively inex-v pensive to manufacture.

With the foregoing and other objects in view, the invention consists of the novel construction, combination and arrangement of parts, as hereinafter more specifically described and illustrated'in the accompanying drawings, wherein is shown an embodiment of the invention, but it is to be understood that changes, variations and modifications can be resorted to which come within the scope of the claims hereunto appended.

More specifically stated the invention in its broad conception consists in constructing and arranging the grate bars to conjointly form draught slits disposedin directions oblique to the medianlines of the bars, the said slits being preferably disposed in opposite directions.

In the drawings wherein like reference characters denote corresponding throughout the several views Figure 1 is a. plan View of a plurality of grate bars in accordance with this invention, of the double ported type.

Figure 2 is a top plan view of a grate bar in accordance with this invention, of the double ported type.

Figure 3 is an inverted plan, of a grate bar in accordance with this invention, of the double ported type. Figure 4 is a section on line 4-4, Figure 1.

Figure 5 is a section on line 5-5, Figure 2.

'Figure 6 is a section on line ure 2. V

Figure 7 is a section on line 7-7, Figure 1.

FigureS is a top plan view of a plurality of assembled grate bars in accordance with this invention, of the single ported type.

Figure 9 is a top plan view of the grate bar in accordance with this invention, of a single ported type.

Figure 10 is a side elevation of a grate p arts 6-6, Figbar in' accordance with this invention, of a single ported type.

' Figure llis a section on line 1111,.Figure 8. o

. Figure 12 is a section on line 12-12, Figure 8.

Figure 13 is a fragmentary view, in plan, of a plurality of assembled double ported grate bars of a modified form in accordance with this invention- Figure14 is a section on line 1414, Fig ure 13. I

Figure 15 is a section on line 1515, Figure 18.

Referring to Figures 1 to 7 of the drawings, theybar is of. substantial length and includesa pair of rectangular end portions 1, 2, of substantial height and thickness, and an intermediate portion referred to generally by the reference character 3.

The intermediate portion 3 is formed of a series of transverse parts 4 and a series of longitudinal parts 5. The parts 7 4, as well as the parts 5 are rectangular in contour, and the parts 4 extend in an opposite direction with respect to the parts 5. The width of the'parts 5 is the same as the width of the end portions 1, 2, and are arranged in alignment therewith. The parts 4 extend lengthwise in a perpendicular direction with respect to the length of the parts-5, where by the parts 4 will project beyond the sides of the parts 5. I The parts 4 are alternately disposed with respect to the parts 5.

The upper surface of the parts 5 is plane throughout and arranged in alignment with the upper faces of the end portions 1, 2.

The upper face of each of the parts 4,

from the longitudinal center of the bar, inclines downwardly throughout in opposite directions, as at 6, 7.

The parts 5 are of less height than the parts 4, and the lower faces of the parts 5 are bevelled upwardly in opposite directions, as at 8, 9, but each of the bevels extends from a point removed from. the longitudinal center of the bar and terminates at the sides thereof. The bevels 8, 9, are of materially less length than the length of the oppositely inclined surfaces 6, 7 of the parts 4.

Formed-integral with the lower face of the parts 4, 5, centrally thereof, and also formed integral with the inner-ends of the end portions 2, is a web 10, of materially less thickness than thethickness ofthe end portions 1,. 2. in height from each end thereof towards the center, as clearly shown in Figure 10. The web 10, centrally thereof, is enlarged, as at 11, forthe purpose of reinforcing the same.

In Figure 1, the grate bars are indicated at 12, 13,14 and 15, and the pants 4, 5 of the bar 12 are staggered with respect to the parts 4, 5 of the bar 13, and the parts'4, 5 of the bar 14 are staggered with respect to the parts 4, 5 of the bar 13. This arrangement is carried throughout when the grate is set up, that is to say each adjacent bar has its parts 4, 5, staggered with respect to the other bars. 7

When the bars are arrangedin grate for- The web: gradually increases 7 mation, the bevelled surfaces 8, 9 of the parts a locking bar, as indicated at 18, and the latter is formed of a pair of end portions 19, 20 and an intermediate portion 21.. The locking bar 18 has its intermediate portion 21, at its inner side, provided withsp-aced projections 22 extending a substantial distance from the inner side of said intermediate portion 21,

The intermediate portion 21 has its inner face, at a plurality of spaced points, undercut, as at 23,v and said undercut portions extend downwardly at an inclination and transversely of a part of the lower face of the intermediate portion 21. The upper face of the intermediate portion 21 is formed with a series of spaced depressions. which extend towards the inner side of the portion 21. The bottom of each of the depressions 24 is inclined, as" at 25, and the upper face of an extension 22 forms a continuation I the outer grate bar 12. The projections 26,

in connection with the bevels 8 of the bar 12, form outwardly extending and upwardly inclined air passages 27. The top walls of the undercuts 23, in connection with the inclined surfaces 7, of the grate bar 12, provide inwardly extending and upwardly inclined air passages 28.

The locking bar 18 is provided with a depending web 29 formed integral with the end portions 19 and 20 and with the intermediate portion 21'. I l

The grate bar shown inFigures 1 to 7, is what may be termed a double ported type,

and when a series of the double ported grate bars is assembled in a manner as stated, the air currents meet and alternate at frequent intervals to prevent formation of dead areas, where low' combustion rates with at tention at long intervals are needed, as in round pot furnaces for house heating purposes.

In the form of grate bar as disclosed in Figures 8 to 12, the bar is of substantial length and consists of a pair of rectangular and port-ions 29, 30, and an intermediate portion 31. The end portions and intermediate portion are connected together by a web 32. The intermediate portion is of materially less height than the end portions 29 and 30. The intermediate portion 31 has each side thereof provided with spaced pro- 'jections formed with a downwardly inclined upper face. The projections at one side of the intermediate portion 31 are indicated at 33, and the projections on the other side of the intermediate portion 31 are indicated at 34. The projections 33 are alternately disposed with respect to the projections 34 on the intermediate portion 21. The upper face of the intermediate portion 31 is formed with two series of spaced depressions. The depressions of one series extend in an opposite: direction with respect to the other series and said depressions extend from the longitudinal center of the intermediate portion 31. The depressions of one series are indi cated at 35 and the depressions of the other series at 36. The depressions 35 are alternately disposed with respect to the depressions 36. The bottoms of the depressions 35 are inclined downwardly as at 37, and the upper face 38 of the projections 33 forms a continuation of the bottoms 37 of the depressions 35. The bottoms 39 of the depressions 36 are inclined, and the upper face of the project-ions 34, as indicated at 40, forms a continuation of the bottoms 39 of the depressions 36.

The lower face of the intermediate portion 31 is provided with two series of spaced undercuts and with the undercuts of one series extending in an opposite direction with respect to the undercuts of the other series. The undercuts of one series are indicated at-4 1, and the undercuts of the other series at 42. The undercuts 41 and 42 extend upwardly at an inclination and from a point atone side of the longitudinal center of the intermediate portion 31. The undercut-s 41 are alternately disposed with respect to the undercuts 42. I Y The construction of grate bar disclosed in Figures 8 to 12 is of the single ported type and in Figure 8 a series of single ported bars is shown assembled, andwhich are indicated'at 43, 44,- 45 and 46. The locking bar for the single ported bars is indicated at 47 and is of'the same construction as the locking bar 18 and associates with the outer bar 43 of the series of grate bars, in the same manner as the bar 18 associates with the bar In the single port-ed bar construction the projections 33 of an intermediate bar associate with the undercuts 38 of'an adjacent bar to provide an upwardly and outwardly extending air passage 48. The projections 34 of an intermediate bar associate with the undercuts 42 of an adjacent bar to provide an inwardly extending and upwardly inclined air passage 49.

When the single ported bars are arranged in grate-like .form, there is provided a large number of angular blast openings or ports alternating toright and left across adjacent bars at frequent intervals and causing the opposing air currents to pass each other when high combustion rates are required'as in high pressure boilers for power plants and factory purposes.

In the single ported bars the air is dis charged from all ports of the same hand in the same plane, and the reversing currents pass each other making their entire grate alive, but in the double ported bars, the air currents are opposed and meet in the center of the bar, forming alternative live and dead blocks. The air meeting at the center of the live block is diverted over dead blocks adjoining, and in this manner the whole grate is made alive.

In the modified form shown in Figures 13,14 and 15, the construction is somewhat similar to that shown in Figures 4 to 6, with this exception, that the parts 50, which correspond to the parts 4, have, their oppositely extending inclined surfaces 51 and 52 of less length and greater pitch than the inclined surfaces 6 and 7 and further whereby the side edges 53 of the parts 50 are of greater height than the side edges of the parts 4.

I so

&

Further, the bevelled surfaces 54, of the parts 56, which correspond to the parts 5, are of less length and greater pitch than the bevelled surfaces 8, 9, and further the part 56 has vertical side edges 57 .which oppose has been completely burned. Then further theair currents will materially assist in preventing the escape of thefuel. I I I When the double ported bars are assembled in grate-like form the parts 6 will engage with the underside of the parts 5, and the bars will then be locked together and cannot fall into the ash pit, nor-be pulled out of place when cleaning fires, even if broken, unless a locking bar is first removed. This same arrangement applies to the projections 33 and 34: with respect to the parts of the intermediate part 31 provided with the undercuts 4:1 and 4:2.

What I claim is s 1. A grate bar comprising a substantially elongated body formed of a pair of end portions and an intermediate portion, said intermediate portion having its upper face formed with oppositely disposed spaced downwardly inclined surfaces extending at right angles with respect to the length of the bar, and said intermediate portion further having its lower face provided with oppositely disposed spaced upwardly extended bevel surfaces extending at right angles with respect to the length of the bar and alternately arranged with respect to the said inclined surfaces. I I r 2. A grate bar comprising a substantially elongated body formed of a pair of end portions and an intermediate portion, said intermediate portion having its upper face formed with oppositely disposed spaced downwardly inclined surfaces extending at right angles with respect to the length of the bar, and said intermediate portion further having its lower face provided with oppositely disposed spaced upwardly extended bevel surfaces extending at right angles with respect to the length of the bar and alternately arranged with respect to the said incli-ned surfaces, said inclined surfaces of greater length than said bevelled surfaces and projecting beyond and laterally with respect to the outer termini thereof.

3. A grate bar comprising a substantially elongated body formed of a pair of end portions and anintermediate portion, said intermediate portion having its upper face formed with oppositely disposed spaced downwardly inclined surfaces extending'at ri ht angles with respect tothe length of the bar, said intermediate portion further having its lower face provided with oppositely disposed spaced upwardly extended bevel surfaces extending at right angles with re spect to the length of the bar and alternately arranged with respect vto the said inclined surfaces, and a depending web integral with and of less thickness than said intermediate portion. I i 1 r 4. A grate bar comprising a substantially elongated body formed of a pair of end portions and an intermediate portion, said intermediate portion having its upper face formed with oppositely disposedfspaceddownwardly inclined surfaces extendingi at right angles wit-h respect to the length ofthe bar, said intermediate portion: further having its lower face provided with oppositely disposed spaced upwardly extended bevel surfaces extending at right angles with respect to the length of the bar and alternately.

tions and an intermediate portion, said intermediate portion having its upper face formed with oppositely disposed spaced downwardly inclined surfaces extending at right angles with respect to the length of vthe bar, and said intermediate portionfur-.

ther having its lower face provided with 0ppositely disposed spaced upwardly extended bevel surfaces extending at right angles with respect to the length of the barand alternately arranged with respect to the said inclined surfaces, the parts of said inter.- mediate portion having the inclined surfaces of a length to extend below and in spaced relation with respect to the bevelled surfaces of an adjacent bar to provide angularly disposed air passages and further'to interengage with such adjacent bar.

6. A grate bar comprising a substantially elongated body formed of a pair of end portions and an intermediate portion, said intermediate portion having its upper face formed with oppositely disposed spaced downwardly inclined surfaces extending at right angles with respect to the length of the bar, and said intermediate portion further having its lower face provided with oppositely disposed spaced upwardly extended bevel surfaces extending at right angles with respect to the length of the bar and alternately arranged with respect to the said inclined surfaces, said end portions of throughout the length of the bars and disgreater height than said intermediate porposed in directions oblique to the upper surtion. face of the grate formed by the series of 10 7. A series of grate bars, the adjacent bars bars. 5 of which form shallow draft interstices In testimony whereof, I aflix my signature therebetween, said interstices extending alhereto. ternately in opposite directions substantially ALFRED BALMFIRTH. 

